Chapter 20 + 21

The oral cavity is lined by a   for protection.

The most common cancer of the oral cavity is  

ORAL MUCOSA =   and the  

The 3 parts of the oral mucosa are
1 
2.  
3.  

Masicatory = over 

Lining mucosa = over  like inside of  and 

Specialized mucosa = over  

Masticatory mucosa -- lines the  and  

In  the surface cells produce keratin but the cells retain
shrunken nuclei.

Lining mucosa -- lines the oral side of the ,  ,  , , and  

LIP -- junction between the   and  
- basically a bag of   containing a core of 

Specialized mucosa - lines the  of the  . It contains all the basic
layers of the lining mucosa with the addition of   and .

Taste buds are a chemoreceptor with a  

What are the 4 types of papillae

The tongue is unique in that it has interlacing bundles of  muscle in  
planes of orientation.

The serous glands of the mucosa are referred to as

3 layers of mucosa are

Epithelium - stratified squamous ( ) or simple columnar ( )

Lamina propria - highly  , may contain 

Muscularis mucosae - thin layer of  , present from   to .

SUBMUCOSA -  containing   and ,   may be present

MUSCULARIS EXTERNAE (Muscularis Propria) - usually   ( in part
of the esophagus), commonly arranged in an   and an  .

ADVENTITIA ( ,  ) or SEROSA (  plus  ,  )

Exocrine glands – includes glands that extend down into the 
(present in  ), and glands that extend further down into the   (present
only in the   and  )

Exocrine glands mostly secrete   (except  
glands that secrete  and  )

Lymphoid tissue (nodules and infiltrate) can appear transiently anywhere, but always
present in the   and  .

Meissner’s nerve plexus in   and Auerbach’s nerve plexus (myenteric) in the
 .

The enteric nervous system is made of the  

Auerbach’s plexus mostly regulates
 , while Meissner’s plexus is more involved in  . Ganglion cells are derived from the  

Enteroendocrine cells ( ) - scattered   or   in the
  or   throughout the tract, derived from the  

The esophagus can be identified by the combination of a   with a  .

The muscularis externae differs from that of the rest of the digestive tract in that the upper
third contains  , the middle third contains both  , and
the lower third contains only  . Muscle is arranged into  and
  layers.

  – dilated tortuous veins develop in the submucosa and mucosa of
the esophagus in patients with long standing  . Rupture of these
vessels is a common cause of death in .

 :
This is a complication of long-standing   from the stomach. The   of the distal portion of the esophagus
undergoes   to a  epithelium like that of the intestines (absorptive
simple columnar with goblet cells). This epithelium can become dysplastic and develop
into an  .

Cancer of the esophagus –  malignant,   prognosis

. Squamous cell carcinoma
- develops from  , most  

Adenocarcinoma
- develops from the glands in the   of the
esophagus, associated with  

Generally the   the cancer cells migrate in the organ, the  the prognosis

Criteria for GI carcinomas (4)

The stomach coverts digested foot into  

The stomach has  ,
longitudinal folds of the mucosa and submucosa, which usually disappear when  

Although the surface epithelial cells and many glandular cells of the
stomach secrete mucus they are   classified as goblet cells (different shape).

Cardiac glands = secrete  

Fundic or gastric glands  and  

Pyloric glands  

Pariteal cells are  and are filled with  

Parietal cells have deep folds of cell membrane that form 

Parietal cells secrete   and  

Chief cells are  . They are filled with   and  . Main function is to secrete  .

The enteroendocrine cells are   between cells and   derived. They are   or   secreting cells.

  replace surface and gland cells

There are subtle differences in appearance (shading) between the   and the  . Evident at  junction.

To identify a stomach cell, look for
(1)  ,  (surface description)
(2)  (cell type) with   (not goblet)
(3) Many small mucosal glands   into lamina propria

Cardiac stomach is   next to   (of  ) (cell type)

Fundic stomach is  with   glands with   and   cells filling mucosa

Pyloric stomach is   with  . Pits are long and there is a  it appearance from top of gland to pit.

Gastritis – an inflammation of the
 . In chronic
gastritis   and   increase in number. The
mucosa can atrophy and undergo
 to an intestinal
epithelium. Further dysplasia can
lead to  .

Loss of parietal cells can cause
  and decreased
acid of the  

Ulcer – defined as a breach in the
mucosa extending through the
various . Ulcers
can occur throughout the GI tract,
but are most common in the
  and   where
large amounts of acid are present.

Gastric Carcinoma (adenocarcinoma) - highly carcinomas. A   confined to the mucosa is better than one that extends down into the   layer.

The small intestine, the  portion of the gut, digests food and absorbs
the end-products of digestion.

The   has Brunner’s glands in the
submucosa to help  

The   has Peyer’s patches,
a permanent  

4 modifications of the small intestine that increase absoprition?

 – permanent folds of the mucosa and submucosa

  – finger-like projections of the mucosa

 –downward invaginations
continuous with the villi, in the mucosa

  – on the surface simple columnar epithelium

Brunner's glands look like  , Peyer's patches look like  

The 3 complents of the mucosa of the small intestine are

 - projections of the epithelium and lamina propria

Surface epithelium of Stomach
-   with absorptive and  
- Cells are replaced  

Crypts of Lieberkuhn (intestinal glands)
–   of surface epithelium into lamina propria layer of mucosa
- contains  ,  ,  , , and  .

Submucosa – only the   has glands in the submucosa ( glands)

Goblet cells increase in number from the   to the  

Central lacteals are  in middle of  

Paneth cells are   granules that  

The lamina propria is a   loose CT

DUODENUM - ID
Small intestine with
  gland in
submucosa

JEJUNUM -ID
Small intestines
No  
No  
- Boring

ILEUM
Small intestine with
  patches

Malabsorption is a general term used to describe a number of clinical conditions in
which nutrients, vitamins, and minerals are inadequately absorbed by the GI tract. This
is present in diseases in which there is an atrophy and reduction in the number of   in the small intestines. Sensitivity to  is one of the many causes of
malabsorption

Crohn’s disease – is a chronic idiopathic inflammatory bowel disease that typically
affects the   and/or  . It is characterized by involvement of discontinuous
segments of the intestine (  lesions). In the diseased sections, inflammation
penetrates all the layers of intestine (transmural), causing a thickened, rigid wall and
narrowed lumen. The intestine develops ulcers that appear as narrow fissures that
penetrate deeply into the gut wall

Meckel’s diverticulum – remnant of  , connection of   to  . This common malformation of small intestine can lead to bleeding,
obstruction and perforation.

The large intestine is composed of the  ,  ,  , and  

Most of the large intestine has ,   bands of muscle derived from
the outer longitudinal layer of the  .

In the simple columnar epithelium of the large intestine, there are absorptive cells called  . There ends up being a decreasing amount of   and an increasing about of  

The crypts of lieberkuhn are simple tubular organs with (1)   (2)  (3)  

The muscularis externae layer is the   layer with an   layer in  bands  

The large intestine can be identified because it has a   with  . It is simple columnar with  . There is also taenia coli present but not in every area of large intestine

Where are the 3 places that the taenia coli are not found?

The appendix has a similar strcuture to the colon EXCEPT 1.   2.   3.  

Embryological transition from   to  to  (  line)
with new blood supply and innervation. The   also marks the location of the
original   at the end of the hindgut.

  of rectum to   of anal canal and then to  (white line of  ) continuous with skin. (cell types)

. Appendicitis – usually an   of the  

Carcinoid Tumors (  cell tumors) – uncommon tumor from neural crest
derived enteroendocrine cells in the  . They can secrete a variety of substances,
including  , ,  , and 

Ulcerative colitis – is a chronic idiopathic inflammatory bowel disease typically limited
to the   and . It commonly extends proximally in a continuous fashion from
the rectum. Inflammation, usually limited to the   &   layers, results in
many small ulcers.  cells, which normally are not present, appear in the  
(Paneth cell  ). Long-standing ulcerative colitis may lead to cancer.

Malignant neoplasm in the large intestine thought to develop
from   that have undergone
malignant change

Ischemic bowel disease – a
  of blood flow to the
large and/or small intestines can result in
death. Within 1-4 days, growth of
intestinal bacteria can produce  
and perforation of the bowel.

 , is caused
by a loss of enteric neurons in a section of colon. This can lead to obstruction and